chore: serialize circuit as hex string in build artifact file

[TomAFrench]

Related issue(s)

Resolves #

Description

Summary of changes

We now output the CompiledProgram json file with the circuit represented as a hex string rather than as a long array of byte values. This is more consistent with standard solidity tooling.

Note that this hex is not 0x-prefixed, in case there are strong feelings around this.

Dependency additions / changes

Test additions / changes

Checklist

• I have tested the changes locally.
• I have formatted the changes with Prettier and/or cargo fmt with default settings.
• I have linked this PR to the issue(s) that it resolves.
• I have reviewed the changes on GitHub, line by line.
• I have ensured all changes are covered in the description.

Documentation needs

• This PR requires documentation updates when merged.
  • Relevant to Document CompiledProgram JSON docs#26

Additional context

[guipublic]

Shouldn't we always compress the circuit when serialising it?

[kevaundray]

Shouldn't we always compress the circuit when serialising it?

Compression can be done on the ACVM level when serialize is called instead of on the Noir level.

This is also not a blocker to this PR as its just changing it from being displayed as bytes to a hex string in the build artifact to align more with what solidity does.

[guipublic]

Compression can be done on the ACVM level when serialize is called instead of on the Noir level.

Yes I agree, it should be handled at the ACVM level.